The present invention relates to polyarylate copolymers and alloys. More particularly, this invention relates to 5-keto-bis(hydroxyphenyl)anthracene polyarylate copolymers and alloys having superior thermal properties.
Polyarylates are defined as aromatic polyester polymers derived from dihydroxy aromatic compounds (diphenols) and aromatic dicarboxylic acids.
In general, aromatic polyesters prepared from bisphenols or functional derivatives thereof and a terephthalic acid-isophthalic acid mixture or a mixture of the functional derivatives thereof, i.e., bisphenol terephthalate-bisphenol isophthalate polyesters, have excellent mechanical properties, such as tensile strength, bending strength, bending recovery or impact strength, excellent thermal properties, such as deflection temperature under load or degradation temperature, excellent electrical properties, such as resistivity, electric breakdown endurance, arc resistance, dielectric constant or dielectric loss and low flammability, good dimensional stability, and the like.
These aromatic polyesters are thus useful in many fields. Aromatic polyesters find special use as plastics for injection molding, extrusion molding, press molding, and the like, as monofilaments, fibers, films and coatings.
U.S. Pat. No. 3,216,970 describes polyarylates which include polymers of bisphenol A and isophthalic acid or a mixture of isophthalic acid and terephthalic acid. These polyarylates are prepared by converting the phthalic acid component to the diacid chloride which is then reacted with the bisphenol A or its sodium salt.
U.S. Pat. No. 3,884,990 describes a blend of various bisphenol polyarylates and poly(ethylene oxybenzoate), which is useful for producing molded articles having improved cracking and crazing resistance. Similarly, U.S. Pat. No. 3,946,091 describes a blend of bisphenol polyarylates and poly(ethylene terephthalate) which provides molded articles of reduced crazing.
U.S. Pat. No. 3,792,118 describes a styrene resin composition resistant to heat deformation which comprises a blend of polyarylene esters and various styrene resins.